﻿using GrapeCity.Forguncy.Commands;
using GrapeCity.Forguncy.Plugin;
using Newtonsoft.Json.Linq;
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;

namespace CollectionOperationKit
{
    [Icon("pack://application:,,,/CollectionOperationKit;component/Resources/ArrayIcon.png")]
    [Category("对象与集合操作")]
    public class ServerSideArrayCalc
        : BaseServerCommand, ICommandExecutableInServerSide
    {


        /// <summary>
        /// 在设计器中展示的插件名称
        /// </summary>
        /// <returns>易读的字符串</returns>
        public override string ToString()
        {
            if (Operation == SupportedOperations.SUM)
            {
                if (String.IsNullOrEmpty(OutParamaterName))
                {
                    return "数组统计计算"; // 命令列表中默认显示的名称
                }
                else
                {
                    return "数组统计计算（SUM）：" + OutParamaterName;
                }

            }
            else
            {

                if (String.IsNullOrEmpty(OutParamaterName))
                {
                    return "数组统计计算（" + Operation.ToString() + "）";
                }
                else
                {
                    return "数组统计计算（" + Operation.ToString() + "）：" + OutParamaterName;
                }
            }

        }

        [OrderWeight(100)]
        [DisplayName("输入参数（数组）")]
        [FormulaProperty]
        public object InParamater { get; set; }


        [OrderWeight(110)]
        [DisplayName("操作")]
        [ComboProperty]
        [SearchableProperty]
        public SupportedOperations Operation { get; set; }

        [OrderWeight(120)]
        [DisplayName("属性名")]
        [Description("在该属性名中执行统计计算，%value%则使用数组元素本身。在数值计算时，null将按照0来处理。")]
        [FormulaProperty(AcceptsReturn = true)]
        public object OperationFieldName { get; set; }


        public enum SupportedOperations
        {
            [Description("SUM：求和")]
            SUM,
            [Description("COUNT：计数，仅统计所有非空项目")]
            COUNT,
            [Description("AVG：算术平均值")]
            AVG,
            [Description("MAX：取最大值")]
            MAX,
            [Description("MIN：取最小值")]
            MIN
        }



        public ExecuteResult Execute(IServerCommandExecuteContext dataContext)
        {
            ArrayList data = getArrayListParam(dataContext, this.InParamater);

            IQueryable<object> queryableData = data.Cast<object>().AsQueryable();

            string propName = (string)getParamValue(dataContext, this.OperationFieldName, false);

            // 分别处理各个操作
            switch (this.Operation)
            {

                case SupportedOperations.COUNT:
                    {
                        int result = queryableData.Count(item => ServerSideHelpers.GetObjectProperty(item, propName, true) != null);
                        returnToParam(dataContext, result);
                        break;
                    }
                case SupportedOperations.SUM:
                    {
                        decimal result = 0;
                        result = queryableData.Sum(item => PickupDecimalProperty(item, propName));
                        returnToParam(dataContext, result);
                        break;
                    }
                case SupportedOperations.MAX:
                    {
                        decimal? result = null;

                        if (queryableData.Count() > 0)
                        {
                            result = queryableData.Max(item => PickupDecimalProperty(item, propName));
                        }

                        returnToParam(dataContext, result);
                        break;
                    }
                case SupportedOperations.MIN:
                    {
                        decimal? result = null;

                        if (queryableData.Count() > 0)
                        {
                            result = queryableData.Min(item => PickupDecimalProperty(item, propName));
                        }

                        returnToParam(dataContext, result);
                        break;
                    }
                case SupportedOperations.AVG:
                    {
                        decimal? result = null;

                        if (queryableData.Count() > 0)
                        {
                            result = queryableData.Average(item => PickupDecimalProperty(item, propName));
                        }

                        returnToParam(dataContext, result);
                        break;
                    }
            }


            return new ExecuteResult();
        }


        private decimal PickupDecimalProperty(object item, string propertyName)
        {
            decimal parsedResult = 0;

            if (item != null)
            {
                var value = ServerSideHelpers.GetObjectProperty(item, propertyName, true);
                if (value != null)
                {
                    Decimal.TryParse(value.ToString(), out parsedResult);
                    return parsedResult;
                }
            }

            return parsedResult;

        }
    }
}
